Comprehensive study on the cooling system of high-power semiconductor laser was carried out. Firstly, fluid analysis of the coolant in the channels of the cooling system was conducted, and the corresponding results showed that turbulent cavities were formed easily at the inlet and places with small comprehensive study on the cooling system of high-power semiconductor laser was carried out. Firstly, fluid analysis of the coolant in the channels of the cooling system was conducted, and the corresponding results showed that turbulent cavities were formed easily at the inlet and places with small curvatures. Turbulent cavities may not only cause the cavitation corrosion effect, but also cause the upper fluid channel near the heat source was not fully filled with coolant. In addition, turbulent cavities will also reduce the heat dissipation efficiency of the cooling system; Secondly, based on the traditional fluid channel structure, an optimized atypical macro-channel structure was proposed. The distribution of the heat dissipation model and the distribution of the laser module components were numerically simulated using Fluent that the finite element analysis software. The simulation results showed that no turbulence cavities were generated when the coolant flows in the fluid channel of the optimized model, and the upper layer of the fluid channel can be better filled with coolant. Simultaneously, the optimized model solved the problem of slow fluid velocity in the localized area of fluid channel of the classical model, not only improved the heat dissipation performance of the cooling system, but also improved the reliability of the cooling system. Additionally, according to the temperature field simulation results, the highest working temperature of the laser was decreased by 2 ℃ when applying the optimized cooling system. And the temperature on heat source-1 was more uniformly-distributed, while the temperature on heat source-3 was reduced by 1.25 ℃; Finally, the cooling system experiments were carried out and the results were well-matched with our simulation results.